The writer to the Hebrews wrote this:
Pursue…holiness—without it no one will see the Lord. Make sure that no one falls short of the grace of God and that no root of bitterness springs up, causing trouble and defiling many. (Hebrews 12:14-15)
A lot of people, when they see the phrase “root of bitterness,” think that God is warning against holding bitterness in your heart.
Of course, we shouldn’t hold bitterness in our hearts, but actually, the author of Hebrews is referring to Moses’ words in Deuteronomy 29, where he said,
Be sure there is no man, woman, clan, or tribe among you today whose heart turns away from the Lord our God to go and worship the gods of those nations. Be sure there is no root among you bearing poisonous and bitter fruit. When someone hears the words of this oath, he may consider himself exempt, thinking, ‘I will have peace even though I follow my own stubborn heart.’ This will lead to the destruction of the well-watered land as well as the dry land. (18-19)
According to Moses, what is a root bearing poisonous or bitter fruit? It’s a heart that thinks, “I’m saved. I’m okay. Now I’ll live how I want to.”
Moses warned the Israelites against people like that, saying that such an attitude could spread among the Israelites and destroy them.
The writer of Hebrews takes Moses’ words and warns the church against the same attitude.
That attitude can show itself in many ways, but especially in idolatry. Idolatry is not just worshiping other gods, but putting anything in front of God, whether it’s money, things, pleasure, or whatever else it may be. Anything you put before God is your idol.
But as God’s people, we now serve him. We cannot say, “I’m saved, now I’ll live as I want to.”
God has not taught us everything he knows, but what he has taught us, we are accountable for (Deuteronomy 29:29).
And an attitude of “I’m saved, now I’ll live as I want to” will cause you to fall short of the grace of God in your life.
The grace of God gives us a heart of thanksgiving and a desire to please him. If you don’t have that kind of heart, you don’t really know God’s grace at all.